// beautify-worker.js
// 独立Web Worker脚本，用于CSS代码美化

self.onmessage = function (evt) {
    function Beautifier(source_text, options) {
        options = options || {};
        var indentSize = options.indent_size || 4;
        var indentCharacter = options.indent_char || ' ';

        // compatibility
        if (typeof indentSize === "string") {
            indentSize = parseInt(indentSize, 10);
        }

        // tokenizer
        var whiteRe = /^\s+$/;
        var wordRe = /[\w$\-_]/;

        var pos = -1, ch;

        function next() {
            ch = source_text.charAt(++pos);
            return ch;
        }

        function peek() {
            return source_text.charAt(pos + 1);
        }

        function eatString(comma) {
            var start = pos;
            while (next()) {
                if (ch === "\\") {
                    next();
                    next();
                } else if (ch === comma) {
                    break;
                } else if (ch === "\n") {
                    break;
                }
            }
            return source_text.substring(start, pos + 1);
        }

        function eatWhitespace() {
            var start = pos;
            while (whiteRe.test(peek())) {
                pos++;
            }
            return pos !== start;
        }

        function skipWhitespace() {
            var start = pos;
            do {
            } while (whiteRe.test(next()));
            return pos !== start + 1;
        }

        function eatComment() {
            var start = pos;
            next();
            while (next()) {
                if (ch === "*" && peek() === "/") {
                    pos++;
                    break;
                }
            }
            return source_text.substring(start, pos + 1);
        }

        function lookBack(str) {
            return source_text.substring(pos - str.length, pos).toLowerCase() === str;
        }

        // printer
        var indentString = source_text.match(/^[\r\n]*[\t ]*/)[0];
        var singleIndent = Array(indentSize + 1).join(indentCharacter);
        var indentLevel = 0;

        function indent() {
            indentLevel++;
            indentString += singleIndent;
        }

        function outdent() {
            indentLevel--;
            indentString = indentString.slice(0, -indentSize);
        }

        var print = {};
        print["{"] = function (ch) {
            print.singleSpace();
            output.push(ch);
            print.newLine();
        };
        print["}"] = function (ch) {
            print.newLine();
            output.push(ch);
            print.newLine();
        };

        print.newLine = function (keepWhitespace) {
            if (!keepWhitespace) {
                while (whiteRe.test(output[output.length - 1])) {
                    output.pop();
                }
            }
            if (output.length) {
                output.push('\n');
            }
            if (indentString) {
                output.push(indentString);
            }
        };
        print.singleSpace = function () {
            if (output.length && !whiteRe.test(output[output.length - 1])) {
                output.push(' ');
            }
        };
        var output = [];
        if (indentString) {
            output.push(indentString);
        }
        /*_____________________--------------------_____________________*/

        while (true) {
            var isAfterSpace = skipWhitespace();
            if (!ch) {
                break;
            }
            if (ch === '{') {
                indent();
                print["{"](ch);
            } else if (ch === '}') {
                outdent();
                print["}"](ch);
            } else if (ch === '"' || ch === '\'') {
                output.push(eatString(ch));
            } else if (ch === ';') {
                output.push(ch, '\n', indentString);
            } else if (ch === '/' && peek() === '*') { // comment
                print.newLine();
                output.push(eatComment(), "\n", indentString);
            } else if (ch === '(') { // may be a url
                if (lookBack("url")) {
                    output.push(ch);
                    eatWhitespace();
                    if (next()) {
                        if (ch !== ')' && ch !== '"' && ch !== '\'') {
                            output.push(eatString(')'));
                        } else {
                            pos--;
                        }
                    }
                } else {
                    if (isAfterSpace) {
                        print.singleSpace();
                    }
                    output.push(ch);
                    eatWhitespace();
                }
            } else if (ch === ')') {
                output.push(ch);
            } else if (ch === ',') {
                eatWhitespace();
                output.push(ch);
                print.singleSpace();
            } else if (ch === ']') {
                output.push(ch);
            } else if (ch === '[' || ch === '=') { // no whitespace before or after
                eatWhitespace();
                output.push(ch);
            } else {
                if (isAfterSpace) {
                    print.singleSpace();
                }
                output.push(ch);
            }
        }
        var sweetCode = output.join('').replace(/[\n ]+$/, '');
        return sweetCode;
    }
    var result = Beautifier(evt.data.source_text, evt.data.options);
    self.postMessage(result);
};